Full or partial dentures are manufactured according to basically known methods. These include, e.g., the conventional methods involving powder/liquid technology that have been known for a long time and are described in the literature (e.g. EP 1 243 230 A2, U.S. Pat. No. 6,881,360 B2 and “Dental Materials” in: Ullmann's Encyclopedia of Industrial Chemistry, Copyright 2002 by Wiley-VCH Verlag).
In general, three different main classes of materials for the manufacture of full dentures are known. These are polymethylmethacrylate (PMMA)-based two component materials [commercially available as Palapress, Paladur (Heraeus Kulzer, DE), SR 3/60® Quick (Ivoclar, LI), Degupress® (Degussa-Hüls, DE)]; PMMA-free hot-curing materials [commercially available, e.g., as Paladon® 65 (Heraeus Kulzer, DE), SR 3/60®, SR Ivocap® (Ivoclar, LI), Lucitone® (Dentsply, US)] and injection moulded masses for thermoplastic processing.
Thermoplastic materials are heated and injected into a hollow space, usually through an injection moulding method. A known method called “Polyapress®” is distributed, amongst others, by Bredent, Senden (DE). There have been numerous attempts to use polymers such as PVC, polyurethane, polyamide or polycarbonate (Ullmann's loc. cit. 5.1.5. Other Denture Resins.)
Moreover, there are methods that are based on light- or microwave-cured 1-component materials (e.g. Versyo.com® made by Heraeus Kulzer); (Ullmann's loc. cit. 5.1.3. Light-Cured Polymers, 5.1.4. Microwave-Cured Polymers).
The work steps required for preparation of the processing of the plastic materials are the same for all of these materials.
Moreover, techniques for the build-up of layers are known in dental engineering. These are used in combination with light-curing materials in most cases, for example for veneering metal crowns or production of a denture. The advantages of said methods include the level of control over the procedure and the ability to vary the colours in order to attain aesthetically pleasing dental work.
The use of Rapid Prototyping1 methods in dental engineering has also been proposed. These involve working with layers that can be polymerised (DE 101 14 290 A1, DE 101 50 256 A1) or with ink jet powder printing (U.S. Pat. No. 6,322,728 B1). 1 Rapid Prototyping (German: schneller Prototypenbau) is a method for rapid production of sample components based on design data. Accordingly, rapid prototyping methods are manufacturing methods aiming to implement existing CAD data directly and rapidly in work pieces, if possible without manual detours or moulds. The relevant data interface for this group of methods is the STL format. The methods that have become known by the name of Rapid Prototyping since the 1980s are usually primary forming methods that build-up the work piece in layers from shapeless or neutral-shape material utilising physical and/or chemical effects.
Essentially, the production of full dentures involves the following steps, as illustrated in FIG. 2:                dentist taking a silicone impression;        fabrication of a dental plaster model by the dental technician to reflect the shape of the jaw;        setting-up the artificial teeth in wax and carving the gingiva;        trying-in and correcting, if applicable, done by the dentist or the dental laboratory;        investing the corrected wax denture in dental plaster, silicone or agar-agar;        removing the wax by boiling it out with hot water;        inserting the artificial teeth in the mould thus produced;        filling the hollow space thus generated with a denture plastic material (e.g. PalaXpress®);        polymerising, finishing, and polishing the final denture.        
Attempts are being made to an increasing degree to simplify this complex procedure. Accordingly, Heraeus Kulzer presented the Filou 28 product (EP 1 704 831 A1) at the IDS 2005. This was the first attempt to reduce the time needed for setting-up the artificial teeth in wax.